package storage

import (
	"context"
	"fmt"

	"github.com/spf13/viper"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"gopkg.in/mgo.v2/bson"
)

type MongoDBStorage struct {
	*mongo.Client
	DbName      string
	Collections map[string]string
}

func NewMongoDBStorage(cfg *viper.Viper) (MongoDBStorage, error) {
	var (
		mongodb_host   = cfg.GetString("storage.db.mongodb.host")
		mongodb_port   = cfg.GetString("storage.db.mongodb.port")
		mongodb_dbname = cfg.GetString("storage.db.mongodb.db_name")
		mongodb_events = cfg.GetString("storage.db.mongodb.collections.events")
	)

	client, err := mongo.NewClient(options.Client().ApplyURI("mongodb://" + mongodb_host + ":" + mongodb_port))
	if err != nil {
		return MongoDBStorage{}, err
	}

	err = client.Connect(context.TODO())

	if err != nil {
		return MongoDBStorage{}, err
	}

	storage := MongoDBStorage{
		Client: client,
		DbName: mongodb_dbname,
		Collections: map[string]string{
			"events": mongodb_events,
		},
	}
	//TODO Indexes
	return storage, err
}

func (s MongoDBStorage) CreateEvent(event Event) error {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["events"])
	if _, err := collection.InsertOne(context.TODO(), event); err != nil {
		return err
	}

	return nil
}

func (s MongoDBStorage) GetEvent(id string) (*Event, error) {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["events"])

	event := &Event{}
	if err := collection.FindOne(context.TODO(), bson.M{"_id": id}).Decode(event); err != nil {
		return nil, err
	}

	return event, nil
}

func (s MongoDBStorage) GetEvents(namespaces []string) (events []Event, err error) {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["events"])

	var cur *mongo.Cursor

	findOptions := options.Find()
	//findOptions.SetSort(bson.D{{"startdate", 1}})

	if len(namespaces) == 0 {
		cur, err = collection.Find(context.TODO(), bson.D{}, findOptions)
		if err != nil {
			fmt.Println("...")
			fmt.Println(err)
			return events, err
		}
	} else {
		cur, err = collection.Find(context.TODO(), bson.M{"namespace": bson.M{"$in": namespaces}}, findOptions)
		if err != nil {
			fmt.Println("Error here")
			fmt.Println(err)
			return events, err
		}
	}

	for cur.Next(context.TODO()) {
		var event Event
		//var elem bson.M

		if err := cur.Decode(&event); err != nil {
			return events, err
		}

		// fmt.Println(elem)

		// bsonBytes, _ := bson.Marshal(elem)
		// fmt.Println(string(bsonBytes))
		// bson.Unmarshal(bsonBytes, &event)

		events = append(events, event)

	}

	return
}

func (s MongoDBStorage) AddSubscription(eventid string, subscription Subscription) error {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["events"])

	filter := bson.M{"_id": eventid}
	push := bson.M{"$push": bson.M{"subscriptions": subscription}}

	_, err := collection.UpdateOne(context.TODO(), filter, push)
	return err
}

func (s MongoDBStorage) UpdateSubscription(eventid string, subscriber string, deletesubscription Subscription) error {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["events"])

	event := &Event{}
	if errr := collection.FindOne(context.TODO(), bson.M{"_id": eventid}).Decode(event); errr != nil {
		return errr
	}

	for i := range event.Subscriptions {
		if event.Subscriptions[i].Subscriber == subscriber {
			filter := bson.M{"_id": eventid}
			push := bson.M{"$push": bson.M{"deletedsubscriptions": deletesubscription}}
			pull := bson.M{"$pull": bson.M{"subscriptions": bson.M{"subscriber": subscriber}}}
			_, er := collection.UpdateOne(context.TODO(), filter, push)
			if _, err := collection.UpdateOne(context.TODO(), filter, pull); err != nil {
				return err
			}
			return er
		}
	}
	return nil
}

func (s MongoDBStorage) UpdateEvent(event Event) error {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["events"])
	if _, err := collection.ReplaceOne(context.TODO(), bson.M{"_id": event.ID}, event); err != nil {
		fmt.Println(err)
		return err
	}

	return nil
}

func (psql MongoDBStorage) GetSubscriber(subscriber string) ([]Subscription, error) {
	return nil, nil
}

func (psql MongoDBStorage) GetSubscriptionByUser(subscriber string) ([]Subscription, error) {
	return nil, nil
}